Farmers who raise grain crops often have need for storage facilities for their grain. It is very common for farmers to build and maintain permanent building structures for this purpose. The cost of such structures is high and the lack of sufficient storage space can result in a farmer having to sell his grain crop prematurely at a significant loss in revenue.
A similar problem was addressed some years ago for cattle or dairy farmers having to store silage used to feed cattle, e.g. in the winter. In a manner similar to grain storage, huge permanent structures called silos were commonplace on dairy and cattle farms. However, the cattle farmer was provided with a solution. A method of storing silage in large plastic bags was developed as well as the equipment for accomplishing the new method. A movable machine is equipped with a feed rotor and a huge folded plastic bag that, when unfolded, extends, e.g. to a size of 8 feet in diameter and 200 feet in length. Silage is fed to the rotor and the rotor compacts the silage into the bag. The bag unfolds from the machine as the machine moves away from the bag in response to filling of the bag. The unfolding or extension of the bag and the movement of the machine must be controlled to insure proper filling of the bag. This is accomplished by a stop positioned behind the bag to prevent rearward sliding and a brake mechanism on the machine that can be adjusted to resistively release in response to the pressure that is created as the rotor compresses the silage against the stop, i.e., the machine is pushed forward by force feeding the silage into the bag and against the stop. The force required to move the machine against the resistance by the brake is established as that force required to satisfactorily fill the bag. Numerous patents have been issued based on this concept. Representative of these patents are U.S. Pat. No. 3,687,061 (Eggenmuller), U.S. Pat. No. 4,046,068 (Eggenmuller), U.S. Pat. No. Re 31,810 (Lee) and U.S. Pat. No. 4,337,805 (Johnson, et al).
This process works well for silage but is almost useless for filling a pliable plastic bag with grain. The rotor's teeth used for effectively force feeding silage into the bag simply slide through the more viscous grain particles. Various feed mechanisms have been tried but none have been found satisfactory and the effort to adapt the silage storing method to grain storage was abandoned.
Accordingly, an object of the present invention is to provide a machine and method that is suitable for filling large plastic pliable bags with grain.